Learn all about coaxial speaker cables. Our comprehensive guide covers the pros and cons, specific applications, and DIY tips for optimal audio performance.
Table of Contents
Understanding Coaxial Cables
Coaxial cable is a cable consisting of an inner conductor surrounded by insulating material, a braided metal shield, and an outer protective jacket. It is a shielded and insulated conductive cable. This design provides excellent signal integrity, making it ideal for a variety of applications such as audio, video, and data transmission. It transmits analog and digital electrical signals over radio frequencies from 20 kHz to 300 GHz. People often refer to coaxial cables by the type of connection, such as “RCA” or “XLR.” So you may have used more than one type of coaxial cable without realizing it.
Coaxial Cable Construction
- Center Conductor: The solid or stranded wire that carries the electrical signal. The part of the coaxial cable that does the actual work: it carries the signal and acts as the electrical ground for the cable. They are usually made of copper, but may be steel with a copper coating.
- Dielectric: The insulating material that surrounds the center conductor. The insulator serves to separate the metal shield from the core wire.
- Shield: The metal braid or foil that surrounds the dielectric and provides electromagnetic shielding.
- Jacket: The outer layer of the cable that is not used to carry information but protects the cable from environmental damage
Understanding Coaxial Cables as Speaker Wire
Having explored the fundamentals of coaxial cable construction and functionality, let’s examine why it serves as an excellent choice for speaker connectivity.
Speaker coaxial cables offer a professional-grade solution for transmitting audio signals from amplifiers or receivers to speakers. Their robust construction and superior shielding make them particularly effective for high-fidelity audio transmission.
Many audio systems, especially those with powered subwoofers, utilize RCA coaxial connections. For those familiar with traditional speaker wire termination, the process of assembling coaxial speaker cables follows similar principles.
The conversion process involves carefully removing the connectors, stripping the shielding, and repurposing the braided shield as one conductor while using the center core as the other. This creates a high-quality, dual-conductor speaker cable capable of delivering exceptional audio performance.
Advantages of Coaxial Speaker Cables
Less signal loss, thicker conductor and insulation layer
- Low-loss transmission: The electric field between the center conductor and the outer conductor of the coaxial cable is concentrated in the medium, reducing the radiation loss of energy, thereby achieving low-loss long-distance signal transmission.
- Impedance matching: The characteristic impedance of the coaxial cable is relatively stable, which is easy to achieve impedance matching, reduce signal reflection, and improve transmission efficiency.
- Strong anti-interference: The outer conductor layer has a good shielding effect on electromagnetic interference, effectively suppressing the interference of external noise on the signal.
Excellent short-distance transmission effect
- Good high-frequency characteristics: The high-frequency characteristics of coaxial cable are excellent, suitable for the transmission of high-frequency signals, such as video signals, digital audio signals, etc.
- High bandwidth: Due to its structural characteristics, coaxial cable has a higher bandwidth and can transmit more information.
Strong durability
- Good mechanical properties: The outer sheath of the coaxial cable is usually made of wear-resistant and corrosion-resistant materials, has good mechanical properties, and can adapt to harsh environments.
- Strong anti-interference ability: The outer conductor layer has a good shielding effect on electromagnetic interference, protecting the internal signal from external interference.
Reasonable price
- Low production cost: Compared with transmission media such as optical fiber, the production cost of coaxial cable is low.
- Market popularity: Coaxial cable is widely used, the market is mature, and the price is relatively stable.
Strong anti-interference ability
- Good shielding effect: The outer conductor layer has a good shielding effect on electromagnetic interference, effectively suppressing the interference of external noise on the signal.
- Anti-common mode interference: The structural characteristics of coaxial cable make it have a strong suppression ability against common mode interference.
Disadvantages of Coaxial Speaker Cables
The coaxial cable is thicker and not easy to hide
- Physical characteristics: The structure of coaxial cable determines its thicker diameter. The superposition of the center conductor, insulation layer and shielding layer makes the cable relatively large.
- Installation restrictions: The thicker wire diameter limits its wiring in small spaces, such as walls, floors, etc. In environments such as home theaters, it may affect the overall appearance.
- Insufficient flexibility: The thick wire diameter leads to a larger bending radius of the cable, poor flexibility, and it is not easy to carry out complex routing.
Long-distance transmission will cause signal loss
- Attenuation effect: The signal will encounter resistance during transmission, resulting in attenuation of signal energy. The attenuation of coaxial cable is related to factors such as frequency, cable length and material.
- Crosstalk interference: When transmitting over long distances, the impact of external electromagnetic interference on the signal will be more significant, resulting in signal distortion.
- Impedance mismatch: When transmitting over long distances, the mismatch of cable impedance will cause reflections and signal loss.
May be too professional for general home audio
For general home audio systems, the performance provided by coaxial cables may exceed actual needs. Compared with other speaker cables, the cost performance is not high enough, and the installation of coaxial cable requires certain professional knowledge and skills, which is difficult for DIY users.
Does not support the latest high-quality audio formats (such as Dolby TrueHD)
The bandwidth of traditional coaxial cable is limited and cannot transmit high sampling rate and high bit rate audio signals. And some coaxial cable interfaces do not support the latest audio formats.
Impedance matching problem
Signal reflection: Coaxial cable is usually 50/75 ohms, while speakers are usually 14-16 ohms. Impedance mismatch will cause signal reflection and cannot be effectively transmitted to the speakers, causing signal loss and distortion, affecting sound quality. In order to solve the impedance mismatch problem, an impedance matcher is needed, which increases the complexity of the system.
About Impedance
Impedance is a critical factor in coaxial speaker cable performance that directly impacts audio quality. For optimal signal transfer, 75-ohm rated coaxial cables are recommended for speaker connections. Higher impedance generally correlates with better sound quality, as it represents the cable’s total electrical resistance.
The significance of impedance matching differs between analog and digital signals. Analog signals demonstrate more tolerance to impedance mismatches, often continuing to transmit with varying degrees of quality degradation. In contrast, digital signals require precise impedance matching, as they operate in a binary state – either achieving perfect transmission or complete signal failure.
When to Avoid Coaxial Speaker Cable
- Standard home audio systems
- Cost-sensitive projects
- Complex installations that require a high degree of flexibility
- Systems that require specific impedance matching
- DIY projects and quick installations
Coaxial Speaker Cable Selection Recommendations
- RG11 (14 AWG) is best suited for speaker cables
- RG58 and RG59 are not recommended (too small)
- RG-6 is not recommended (metal shielding design is not suitable for speakers)
- RG213/U is recommended for high-power applications
- It is recommended to use specialized coaxial audio cables instead of standard coaxial cables
| Cable Type | Core diameter | Outer diameter | Impedance | Use |
|---|---|---|---|---|
| RG-6/U | 1.024MM | 6.86MM | 75Ω | Cable TV,satellite,cable modems |
| RG-6/UQ | 1.024MM | 7.57MM | 75Ω | Same as RG-6/U but with better shielding |
| RG-7 | 1.3MM | 8.13MM | 75Ω | Same as RG-6/U |
| RG-8/U | 2.17MM | 10.3MM | 50Ω | Amateur radio |
| RG-8/X | 1.47MM | 6.1MM | 50Ω | Same as RG-8/U |
| RG-11/U | 1.63MM | 10.5MM | 75Ω | Same as RG-7 but with lower lasses |
| RG-58/U | 0.81MM | 5MM | 50Ω | Amateur radio,radio communications, Ethernet |
| RG-59/U | 0.64MM | 6.1MM | 75Ω | HQ HD video signal transmission over short distances |
| RG-60/U | 1.024MM | 10.8MM | 50Ω | HD cable TV,High-speed cable internet |
How to DIY Coaxial Speaker Cable?
If your speakers support RCA or XLR connectors, you can easily connect them to the speakers via coaxial cable.If not, you will need to use a DIY method to connect the coaxial cable to the speakers…You can follow the steps below:
- Measure the length: Measure the distance between the sound source device (such as an amplifier) and the speaker, and leave some margin.
- Cut the cable: According to the measurement results, use a knife to cut the coaxial cable to the appropriate length.
- Strip the outer sheath: Use a utility knife or razor blade to carefully strip the plastic protective layer on the outer layer of the cable to expose the inner shield and core wire. Minimize the exposed space to prevent signal loss.
- Process the shield layer: Twist the braided shield layer into a strand, which is usually grounded and corresponds to the black terminal on the speaker and device.
- Process the core wire: Strip the insulation layer on the outer layer of the core wire to expose the copper core. The core wire usually corresponds to the red terminal on the speaker and device.
- Connect the connector: Solder or connect the processed shield layer and core wire to the corresponding terminal on the speaker and device respectively.
- Secure the connection: Wrap the connection with heat shrink tubing or insulating tape to prevent poor contact and short circuits.
Coaxial Speaker Cable Types
Coaxial speaker cables are mainly divided into two types: flexible coaxial and semirigid coaxial. Flexible cables are easy to bend and flexible to install, but the shielding effect is relatively poor; semi-rigid cables have better shielding and strong anti-interference ability, but are less flexible. Although semirigid cables have an advantage in sound quality, flexible cables can also provide good sound quality performance. Triaxial cables, twin coaxial cables, and twin axial cable types can also be used, but their additional features may complicate the process and fail to provide feasible results.
Coaxial Digital Audio Cable
Coaxial digital audio cable is a commonly used digital interface in audio systems. It uses a coaxial cable structure to transmit audio signals digitally. Compared with analog RCA cables, coaxial digital audio cables have better anti-interference ability and fidelity. At the same time, it is more durable than optical fiber cables and has a longer transmission distance, which is suitable for connecting various audio devices. Whether you want to build a home theater or a professional recording studio, coaxial digital audio cables are a reliable choice. Coaxial digital audio cables have two advantages over TOSLINK optical cable solutions: the former is more durable and can work properly at distances of more than 15 feet. TOSLINK cables can actually break due to bending.
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Conclusion
Coaxial speaker cables offer a compelling solution for audio applications that require high signal integrity and durability. By carefully considering the specific requirements of your audio system, you can select the right coaxial cable to achieve optimal performance.
